Speaking at the opening of parliament today, Ghani said Afghan forces had dislodged Islamic State loyalists from regions of Nangarhar province bordering Pakistan.
He says Afghanistan will be a "graveyard" for IS.
IS has had a presence in Afghanistan for more than a year. Officials have said most militants calling themselves IS are disaffected Taliban fighters.
Afghan forces have claimed victory following a 21-day operation in the Achin and Shinwar districts of Nangarhar, claiming at least 200 militants killed.